I was asked this question recently and did not have an answer ready.
I will cover New South Wales and Queensland (as I received legal training in Queensland but work in New South Wales) and will only focus on the criminal aspect and not the administrative aspect (i.e. I am sure if a Police Officer or Teacher cheated on a drug test in NSW or Queensland there would be a way to punish them with public servant legislation i.e. Police Powers and Responsibilities Act [Qld]).
What is adulteration?
Put simply, the addition of anything to the sample you provided (whether it is urine, blood or saliva) to be given a 'negative' (false negative) test result when you may be under the influence of a drug.
Is it Legal in New South Wales?
The majority of offences in New South Wales are outlined in the Crimes Act 1900 (NSW). I do not believe Division 3 - Contamination of Goods applies here as the urine nor the device were to be sold and interfering with it is not likely to cause public anxiety regarding the urine or device.
Potentially, Section 192G - Intention to defraud by false or misleading statement would apply as you are signing a statement on all standard COC forms that the specimen provided is your own, which it is not if it has been adulterated, therefore gaining financial advantage (i.e. keeping a Centrelink benefit or your job, which you would reasonably believe you would lose had you not provided a deceptive sample, would be defrauding the relevant body.
IF PROSECUTED, THE MAXIMUM PENALTY IS IMPRISONMENT FOR FIVE (5) YEARS
Another section that comes to mind is Section 307B - False or Misleading information. This makes it an offence to provide any false information or omit information (such as your drug use status) however this offence only applies if;
The information is given to a Public Authority (any NSW Government or Federal body) or;
The information is given to someone performing a job on behalf of a government body (i.e. if I was testing pilots on behalf of CASA, it would make the false statement an offence)
The information is given in compliance or purported compliance with a law of NSW. (i.e. a renewal of a licence that requires a drug test or random testing of a police officer).
IF PROSECUTED THE MAXIMUM PENALTY IS IMPRISONMENT FOR TWO (2) YEARS AND/OR A FINE OF UP TO 200 PENALTY UNITS
Is it legal in Queensland?
The majority of offences in Queensland are outlined in the Criminal Code Act 1899 (Qld).
Whilst it would be a stretch, I could imagine in circumstances similar to those I outlined with NSW's Section 192G (continuing to receive a benefit or wage after you have provided false information) that potentially Section 408C of the Criminal Code Act would apply as it does make it illegal for a person to dishonestly gain a benefit or advantage, pecuniary or otherwise, for any person.
IF PROSECUTED THE MAXIMUM PENALTY IS IMPRISONMENT FOR FIVE (5) YEARS
Conclusion (NSW) - I think it would be very possible, but not very common, to prosecute an individual who has provided a false sample for testing, certifying it as their own specimen. I am not aware of this being commonplace outside of government agencies however the legislation may cover private employers.
Conclusion (Qld) - I think it would be less likely to successfully prosecute someone in Queensland. And I have personal knowledge of cases where people have presented false documents to their employers, gained a $550,000 advantage they were not entitled to and simply got a 2 year suspended sentence, so it really isn't worth prosecution as Queensland has some of the softest magistrates in the Country.